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Schedule 7 January 30, 1915 

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DEPARTMENT OF THE INTERIOR 

U.S BUREAU OF MINES 

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JOSEPH A. HOLMES, Director 


PROCEDURE FOR ESTABLISHING A LIST OF 
PERMISSIBLE MINERS’ SAFETY LAMPS 

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CHARACTER OF TESTS, CONDITIO^ UNDER 
WHICH LAMPS WILL BE TESTED, 

AND FEES 



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WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1915 

Collected seL 


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n. of o. 

FEB 24 1915 





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PROCEDURE FOR ESTABLISHING A LIST OF PERMISSIBLE MINERS' SAFETY 
LAMPS; CHARACTER OF TESTS, CONDITIONS UNDER WHICH LAMPS 
WILL BE TESTED, AND FEES. 


PRELIMINARY STATEMENT. 

AUTHORIZATION. 

An act of Congress (37 Stat., 681) approved February 25, 1913, 
contains the following provision in regard to tests or investigations 
performed by the Bureau of Mines: 

That for tests or investigations authorized by the Secretary of the Interior under 
the provisions of this act, other than those performed for the Government of the United 
States, or State governments within the United States, a reasonable fee covering the 
necessary expenses shall be charged, according to a schedule prepared by the Director 
of the Bureau of Mines, and approved by the Secretary of the Interior, who shall 
prescribe rules and regulations under which such tests or investigations may be made. 
All moneys received from such sources shall be paid into the Treasury to the credit of 
miscellaneous receipts. 

The Bureau of Mines is prepared, at its Pittsburgh experiment 
station, to conduct tests of miners’ flame safety lamps for the purpose 
of establishing a list of permissible safety lamps for use in mines in 
which explosive gas is liberated. This schedule of tests is submitted 
for the information of those who may desire to submit a type of lamp 
for test. 

DEFINITION OF PERMISSIBLE. 

The Bureau of Mines considers a miners’ safety lamp to be permis¬ 
sible for use in gaseous mines if the details of the construction of the 
lamp are the same as those of the type of lamp that has passed the 
tests made by the bureau and hereinafter described. 

CONDITIONS UNDER WHICH LAMPS WILL BE TESTED. 

The conditions under which the Bureau of Mines will examine, 
inspect, and conduct tests on miners’ safety lamps are as follows: 

1. The examination, inspection, and tests will be made at the 
experiment station of the Bureau of Mines at Pittsburgh, Pa. 

2. Applications for inspection, examination, and test shall be made 
to the Director, Bureau of Mines, Washington, D. C., and shall be 
accompanied by a complete description of the lamp and a set of 
drawings showing all the details of the lamp’s construction. 

76219°—15 3 


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PERMISSIBLE MINERS ’ SAFETY LAMPS. 


3. The applicant for the inspection, examination, and test will be 
required to furnish two lamps of each type, which shall be sent 
prepaid to the engineer in charge of lamp testing, Bureau of Mines, 
Fortieth and Butler Streets, Pittsburgh, Pa., and will be retained by 
the bureau as a laboratory exhibit. 

Each lamp shall have marked on it in a distinct manner the name 
of the manufacturer and the name, letter, or number by which the 
type is designated for trade purposes, and a statement shall be made 
whether or not the lamp is ready to be marketed; also a statement 
describing the fuel used, its trade name, and properties. The appli¬ 
cant may supply the fuel for the test if he so desires. 

4. Upon the receipt of a lamp for which application has been made 
for examination, inspection, or test, the engineer in charge of lamp 
testing will advise the applicant whether additional spare parts are 
deemed necessary to facilitate a proper test of the lamp, and the 
applicant will be required to furnish such parts as may be requested. 

5. No lamp will be tested unless the type submitted is in the com¬ 
pleted form in which it is to be placed on the market. 

6. Only the engineer in charge of lamp testing, his assistants, and 
one representative of the applicant will be permitted to be present 
during the conduct of the tests. 

7. The conduct of the tests shall be entirely under the direction of* 
the bureau’s engineer in charge of the investigation. The tests will 
be made in accordance with a predetermined schedule, which is 
outlined herein. 

8. As soon as possible after the receipt of the formal application 
for test the applicant will be notified of the date on which his lamp 
will be tested, and the amount and character of additional material 
it will be necessary for him to submit. 

9. The tests will be made in the order of the receipt of applications 
for test, provided the necessary lamps and material are submitted 
at the proper time. 

10. The details of the results of the tests shall be regarded as con¬ 
fidential by all present at the tests, and shall not be made public in 
any way prior to their official announcement by the Bureau of Mines. 

11. The results of tests made on lamps that fail to pass the require¬ 
ments shall not be made public but shall be kept confidential, except 
that the person submitting the lamp will be informed with a view 
of possible remedy of defects in future lamps submitted, but such 
changes, other than changing the glass globe or chimney, will not 
be permitted while the testing is in progress. 

12. Tests will be made for manufacturers, manufacturers’ agents, 
State mine inspectors, and mine operators. 

13. A list of permissible lamps and the results of their tests will 
be made public from time to time by the Bureau of Mines. 


PERMISSIBLE MINERS ’ SAFETY LAMPS. 


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14. The glass globe or chimney shall be marked in a distinct 
manner by a name or design by which its type is designated for 
trade purposes. 

GENERAL REQUIREMENTS FOR LAMPS. 

1. The lamp must be provided with double gauzes or with some 
other adequate arrangement serving the same purpose. Every 
gauze must be of steel or best charcoal annealed iron wire of not 
larger than 27 Brown & Sharpe gage (0.014 inch in diameter), 
with 28 meshes to the lineal inch (784 to the square inch), nor less 
than 29 Brown & Sharpe gage (0.01125 inch in diameter) with 29 
meshes to the lineal inch (841 to the square inch). 

2. If lamp standards are used, the standards must be so arranged 
that a straight line touching the exterior part of any two consecutive 
standards will not touch the glass. 

3. The lamp must be so constructed that it will not be possible 
without easy detection to assemble the component parts of the lamp 
without the gauze. 

4. The lamp must be provided with an efficient locking device to 
prevent the fuel vessel, glass, or bonnet from being removed by 
unauthorized persons, or being loosened to such an extent that the 
safety of the lamp is impaired. Provision shall also be made for 
taking up the play due to wear of the screw threads. 

5. The glass globes shall have their two ends as nearly parallel 
as it is practicable to make them. 

6. The lamp will be examined in respect to its general design, 
strength, and general character of construction. 

CHARACTER OF TESTS. 

MECHANICAL TESTS. 

1. The lamp is dropped by means of a mechanical arrangement 
onto a wooden floor from a height of 6 feet, measured from the 
floor to the bottom of the lamp, which has been fitted together 
complete with the glass, a component part of the lamp. 

Five successive trials are made, the lamp being fitted with a dif¬ 
ferent glass each time. The lamp passes the test if the glass is 
broken in not more than one of the five trials. Should the glass be 
broken in two, but not more than two, of the five trials, the lamp is 
submitted to five more trials with fresh glasses, and if the glass breaks 
in two of them the lamp will be considered as having failed to pass the 
test. 

2. A weight of 5 pounds is dropped from a height of 6 feet onto 
the lamp standing vertically on a wooden platform beneath the 
weight. 


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PERMISSIBLE MINERS ’ SAFETY LAMPS. 


The height of 6 feet is measured between the bottom of the weight 
and the top of the lamp. The weight is a lead disk 3 inches in 
diameter and If inches thick, and is dropped mechanically. 

Should the glass of the lamp break, two more trials are made, each 
with a different glass, and if the glass breaks in either the second or 
third trial, the lamp will be considered as having failed to pass the 
test. 

3. A weight of 10 pounds, attached to a cord, the other end of 
which is secured to the bottom of the lamp, is dropped a distance 
of 6 feet, the lamp being suspended at a height of 7 feet from the 
ground. 

The lamp is gripped by means of claws or slung by means of straps 
fastened around its upper part, above the standards protecting the 
glass. A plate is fastened to the bottom of the lamp and the cord is 
attached to the center of this plate. The weight is a lead disk 4f 
inches in diameter and 1| inches thick. It is dropped mechanically. 

This test is repeated three times. If, as the result of any one of 
these three trials, the security of the lamp is found to be defective in 
any way, the lamp will be considered as having failed to pass the test. 

Tests 1, 2, and 3 are to be made in succession on one lamp. Crack¬ 
ing of the glass will be regarded as a breakage. 

PHOTOMETRIC TEST. 

1. The lamp is required to give a minimum candlepower of 0.30, 
as compared with a pentane standard, during a period of 10 hours. 

TESTS IN AN EXPLOSIVE MIXTURE. 

After a lamp has passed the mechanical tests it will be tested 
by placing the lighted lamp in an explosive mixture of gas and air, 
as follows: 

1. In currents of air and gas containing 8-| per cent of natural gas 
drawn from the Pittsburgh gas mains. In a gallery (lamp gallery 
No. 1) a lamp which has passed the mechanical tests is tested, with a 
fresh glass if necessary, in horizontal, inclined, and vertical currents 
of the explosive mixture of gas and air: 

a. In a horizontal current, velocity 600 to 2,500 feet per minute. 

b. In a 45° descending current, velocity 600 to 2,500 feet per 
minute. 

c. In a 45° ascending current, velocity 600 to 2,500 feet per minute. 

d. In a vertical descending current, velocity 600 to 2,500 feet per 
minute. 

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e. In a vertical ascending current, velocity 600 to 2,500 feet per 
minute. 

Trials will be made at velocities of 600, 800, 1,000, 1,200, 1,500, 
2,000, and 2,500 feet per minute. Into the horizontal current mov- 



PERMISSIBLE MINERS * SAFETY LAMPS. 7 

ing at 1,500 feet per minute the lamp will be suddenly thrust from 
below. 

The duration of each trial is two minutes, and each trial is repeated 
three times. An ignition exterior to the lamp will cause the lamp 
to be rejected. 

2. In a still atmosphere (lamp gallery No. 3) containing 8£ per cent 
of natural gas. The lamp is placed, with a fresh glass if necessary, 
in this inflammable atmosphere for three minutes. Five separate 
determinations will he made. An ignition exterior to the lamp will 
cause the lamp to be rejected. 

TESTS OF GLASSES. 

1. A weight of 1 pound is dropped by means of a mechanical 
arrangement from a height of 4 feet upon the glass placed in a vertical 
position on a wooden floor. The weight is a lead disk 2J inches in 
diameter and one-half inch thick. Twenty glasses of any one kind 
will be tested. Two failures in the twenty will cause the glasses to 
be rejected. 

2. Ten glasses are heated in an air bath to a temperature of 212° F., 
and when at that temperature are removed from the bath and plunged 
into water at a temperature of 60° to 65° F. One failure in ten will 
cause the glasses to be rejected. 

If the lamp has two glasses, the outer glass will be tested by mechan¬ 
ical means only and the inner glass by heating only. 

PRELIMINARY INSPECTION AND TEST. 

Lamps in the course of development may be submitted by manu¬ 
facturers for inspection and preliminary tests with a view to ascer¬ 
taining defective construction or the misapplication of safety princi¬ 
ples. The nature of such inspection and tests will be determined 
by the engineer in charge of lamp testing. 

IGNITER TESTS. 

Lamps having internal igniters will be tested to determine the 
safety and permissibility of the igniter device. The permissibility 
of the lamp will be dependent in part on the result of the tests of the 
igniter device. 

These tests will be made to determine the liability of external igni¬ 
tion when the igniter device is operated in the presence of inflam¬ 
mable mixtures of gas and air under such conditions as may he deter¬ 
mined by the engineer in charge of lamp testing, for each type of 
igniting device. 

Tests will be made to determine: 

1. If external ignition is possible when the igniter is operated in 
still and moving currents of gas and air mixtures. 


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PERMISSIBLE MINERS* SAFETY LAMPS. 


2. To determine if the residue left in the lamp after working the 
igniter device is a source of danger in subsequent use of the lamp in 
inflammable mixtures of gas and air. 

3. To determine the nature of the material used in the igniter 
device. 

The igniter will have passed the tests if no external ignition is 
caused by manipulating the igniter when in position within a double¬ 
gauze safety lamp, or if no external ignition is caused by the use of 
the lamp in inflammable mixtures of gas and air after the igniter has 
been in service. 

Applicants for tests will be required to furnish two complete igniter 
devices and 5 dozen igniter refills, which shall be shipped in sealed 
boxes or packages with the trade name written on the outside and 
addressed to the engineer in charge of lamp testing, Bureau of Mines, 
Pittsburgh, Pa. When known by the applicant, the proximate chem¬ 
ical composition of the igniter tape or point should be furnished and 
the place of its manufacture. 

PROPERTIES OF GAS USED IN THE TESTS. 

The inflammable gas used in these series of tests will be the natural 
gas supplied to the city of Pittsburgh. The composition of this gas 
is approximately: Methane, 83.1 per cent; ethane, 16 per cent; nitro¬ 
gen, 0.9 per cent; carbon dioxide, a trace. 

APPROVAL OF PERMISSIBLE MINERS’ SAFETY LAMPS. 

NOTIFICATION OF MANUFACTURER. 

As soon as the bureau’s engineers are satisfied that a lamp is per¬ 
missible the manufacturer, agent, or applicant, and the mine inspec¬ 
tion departments of the several States shall be notified to that effect. 
As soon as a manufacturer receives formal notification that his lamp 
has passed the tests prescribed by the Bureau of Mines, he shall be 
free to advertise such lamp as permissible. 

SCOPE OF APPROVAL. 

The bureau’s approval of any lamp shall be construed as applying 
to all lamps of the same type as tested, made by the same manufac¬ 
turer, and having the same construction in detail, but to no other 
lamp. 

APPROVAL PLATES. 

The manufacturers of such types of lamps as have passed the tests 
of the bureau may attach a plate containing, or stamp into the metal of 
the lamp, the following inscription: 


PERMISSIBLE MINERS’ SAFETY LAMP. 
U. S. BUREAU OF MINES APPROVAL NO. — 





PERMISSIBLE MINERS* SAFETY LAMPS. 9 

Before claiming the bureau’s approval of any modification of any 
approved type of lamp, the manufacturer shall submit to the bureau 
drawings that show the extent and nature of such modifications. 
Each approval of a permissible lamp will be given a serial number, 
and approvals of modified types will bear the same serial number as 
the original, with the addition of the letters a, b, c, etc. 

WITHDRAWAL OF APPROVAL. 

The bureau reserves the right to rescind, for cause, at any time, any 
approval granted under the conditions herein set forth. 

APPROVAL OF LAMP GLOBES. 

The bureau will, on application, make separate tests of glasses 
manufactured for use in connection with any lamp that has been 
approved by the bureau under the provisions of this schedule. 

Glass globes that fulfill the requirements of the tests will be ap¬ 
proved for types manufactured in every particular like those sub¬ 
mitted that passed the test. 

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APPROVAL OF INTERNAL IGNITERS. 

The bureau will, on application, make separate tests of internal 
igniter devices for use with any type of lamp that has been approved 
by the bureau under the provisions of this schedule. 

Igniters that fulfill the requirements of the tests will be approved 
for types manufactured in every particular like those submitted that 
passed the test. 

FEES FOR TESTING MINERS’ SAFETY LAMPS. 

Careful investigation has been made regarding the necessary 
expenses involved in testing miners’ safety lamps at the Pittsburgh 
experiment station, and the following schedule of fees to be charged 
on and after February 15, 1915, has been established and approved by 
the Secretary of the Interior, in accordance with the provisions of 
the statute previously quoted: 


Preliminary inspection and test. $10. 00 

Complete lamp test.. 50. 00 

Candle power test. 5. 00 

Separate glass globe tests. 5. 00 

Separate igniter tests. 10. 00 


The fees specified above may be increased to cover the cost of test¬ 
ing an unusually complicated type of lamp, and are also subject to 
change upon the recommendation of the Director of the Bureau of 
Mines and the approval of the Secretary of the Interior. 







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PERMISSIBLE MINERS ’ SAFETY LAMPS. 


REMITTANCES AND REFUNDS. 

Manufacturers who submit lamps for tests to determine permissi¬ 
bility for use in gaseous mines will be required to furnish a certified 
check or bank draft that shall cover the total fees required for the 
tests, and shall be made payable to the Secretary of the Interior. 
Such fees shall be received at least one week prior to the date set for 
beginning the tests; otherwise the equipment of the next applicant 
on the list will be tested. 

In the event that any lamp submitted does not pass the complete 
test, the sum of $20 will be refunded to the manufacturer in case the 
failure occurs during the mechanical tests. In case the failure occurs 
after the mechanical tests, no refund will be made. No refund will 
be made for preliminary inspection, or for candlepower test, or for 
separate globe or igniter tests. 

J. A. Holmes, 

Director. 

Approved, January 30, 1915. 

Bo Sweeney, 

Assistant Secretary. 


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